1. Field of the Invention
The invention relates to a test apparatus and test method for communicating with a simulated terminal that simulates the communication function of a mobile communication terminal for transmitting and receiving a radio frequency signal based on a predetermined communication standard, thereby testing the communication function during the execution thereof.
2. Description of the Related Art
After a mobile communication terminal, such as a cellular phone, is newly developed, it needs to be tested whether or not it operates normally in an actual operation environment. However, it is extremely difficult to test whether or not the newly developed communication terminal normally operates, by transmitting and receiving various types of communication test information between this terminal and an already working actual base station.
In view of this, a test apparatus has been proposed which comprises a pseudo base station having a function similar to that of an actual base station, and in which the pseudo base station is connected to a newly developed mobile communication terminal to enable them to transmit and receive various types of communication information and to thereby test whether or not the newly developed mobile communication terminal operates normally (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2014-006618).
Since this type of test apparatus uses, as a test target, a mobile communication terminal as hardware, the test is executed after the mobile communication terminal is formed of hardware. Accordingly, a long period is required for the development of the mobile communication terminal. There is a demand for improvement in the development.
It is possible to realize a pseudo terminal as software, using a general-purpose computer, which terminal simulates the communication function of a mobile communication terminal as a test target, and to connect the pseudo terminal to a pseudo base station by a fixed line to thereby confirm the communication function of the pseudo terminal. In this case, it is simple and preferable to realize a configuration for inputting/outputting a packet including a baseband signal to test the pseudo terminal, and for transmitting/receiving the packet including the baseband signal between the pseudo terminal and the pseudo base station via a network, as is described in Patent Document 2 (see, for example, Jpn. PCT National Publication No. 2010-527173).
However, the test apparatus constructed as the above cannot communicate with the pseudo terminal in a real-time manner unlike the actual operation environment, inevitably resulting in non real-time communication. As a result, the pseudo terminal cannot be accurately evaluated.
More specifically, when the pseudo terminal is realized by a computer, a certain processing time is required for the control of hardware and software resources associated with the computer, which requires a longer signal processing time than a pseudo terminal having an IC dedicated for communication. As a result, real-time communication cannot be realized between the pseudo terminal and the pseudo base station, unlike an actual operation environment.
Furthermore, in a configuration where a packet is transmitted and received between a computer and a pseudo base station via a network, retransmission of a packet due to delay of a packet or loss of the packet may occur, with the result that real-time communication cannot be realized between the pseudo terminal and the pseudo base station, unlike the actual operation environment.
If real-time communication cannot be achieved between the pseudo terminal and the pseudo base station as described above, the test apparatus having the above-mentioned structure cannot accurately evaluate the pseudo terminal because the operation environment becomes different from the actual one.